26ffe81188
function old new delta su_main 448 468 +20 buffer_fill_and_print 179 196 +17 scriptreplay_main 205 208 +3 localcmd 275 277 +2 hash_find 233 234 +1 devmem_main 469 463 -6 install_main 724 716 -8 setusershell 11 - -11 find_pair 187 169 -18 restricted_shell 49 - -49 ------------------------------------------------------------------------------ (add/remove: 0/3 grow/shrink: 5/3 up/down: 43/-92) Total: -49 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
133 lines
3.3 KiB
C
133 lines
3.3 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Mini su implementation for busybox
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*
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* Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
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*/
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#include "libbb.h"
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#include <syslog.h>
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#if ENABLE_FEATURE_SU_CHECKS_SHELLS
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/* Return 1 if SHELL is a restricted shell (one not returned by
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getusershell), else 0, meaning it is a standard shell. */
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static int restricted_shell(const char *shell)
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{
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char *line;
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/*setusershell(); - getusershell does it itself*/
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while ((line = getusershell()) != NULL) {
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if (/* *line != '#' && */ strcmp(line, shell) == 0)
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return 0;
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}
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endusershell();
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return 1;
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}
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#endif
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#define SU_OPT_mp (3)
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#define SU_OPT_l (4)
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int su_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int su_main(int argc UNUSED_PARAM, char **argv)
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{
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unsigned flags;
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char *opt_shell = NULL;
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char *opt_command = NULL;
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const char *opt_username = "root";
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struct passwd *pw;
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uid_t cur_uid = getuid();
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const char *tty;
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char *old_user;
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flags = getopt32(argv, "mplc:s:", &opt_command, &opt_shell);
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//argc -= optind;
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argv += optind;
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if (argv[0] && LONE_DASH(argv[0])) {
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flags |= SU_OPT_l;
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argv++;
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}
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/* get user if specified */
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if (argv[0]) {
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opt_username = argv[0];
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argv++;
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}
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if (ENABLE_FEATURE_SU_SYSLOG) {
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/* The utmp entry (via getlogin) is probably the best way to identify
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* the user, especially if someone su's from a su-shell.
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* But getlogin can fail -- usually due to lack of utmp entry.
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* in this case resort to getpwuid. */
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const char *user;
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#if ENABLE_FEATURE_UTMP
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char user_buf[64];
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user = user_buf;
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if (getlogin_r(user_buf, sizeof(user_buf)) != 0)
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#endif
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{
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pw = getpwuid(cur_uid);
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user = pw ? pw->pw_name : "";
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}
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old_user = xstrdup(user);
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tty = xmalloc_ttyname(2);
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if (!tty) {
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tty = "none";
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}
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openlog(applet_name, 0, LOG_AUTH);
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}
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pw = xgetpwnam(opt_username);
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/* Make sure pw->pw_shell is non-NULL. It may be NULL when NEW_USER
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is a username that is retrieved via NIS (YP), but that doesn't have
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a default shell listed. */
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if (!pw->pw_shell || !pw->pw_shell[0])
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pw->pw_shell = (char *)DEFAULT_SHELL;
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if ((cur_uid == 0) || correct_password(pw)) {
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if (ENABLE_FEATURE_SU_SYSLOG)
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syslog(LOG_NOTICE, "%c %s %s:%s",
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'+', tty, old_user, opt_username);
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} else {
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if (ENABLE_FEATURE_SU_SYSLOG)
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syslog(LOG_NOTICE, "%c %s %s:%s",
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'-', tty, old_user, opt_username);
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bb_error_msg_and_die("incorrect password");
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}
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if (ENABLE_FEATURE_CLEAN_UP && ENABLE_FEATURE_SU_SYSLOG) {
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closelog();
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free(old_user);
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}
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if (!opt_shell && (flags & SU_OPT_mp))
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opt_shell = getenv("SHELL");
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#if ENABLE_FEATURE_SU_CHECKS_SHELLS
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if (opt_shell && cur_uid != 0 && restricted_shell(pw->pw_shell)) {
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/* The user being su'd to has a nonstandard shell, and so is
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probably a uucp account or has restricted access. Don't
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compromise the account by allowing access with a standard
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shell. */
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bb_error_msg("using restricted shell");
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opt_shell = NULL;
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}
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#endif
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if (!opt_shell)
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opt_shell = pw->pw_shell;
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change_identity(pw);
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setup_environment(opt_shell,
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((flags & SU_OPT_l) / SU_OPT_l * SETUP_ENV_CLEARENV)
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+ (!(flags & SU_OPT_mp) * SETUP_ENV_CHANGEENV),
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pw);
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IF_SELINUX(set_current_security_context(NULL);)
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/* Never returns */
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run_shell(opt_shell, flags & SU_OPT_l, opt_command, (const char**)argv);
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/* return EXIT_FAILURE; - not reached */
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}
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